Steam heating boiler control



April T. w. H. ABBOTT ,346,

STEAM HEATING BOILER CONTROL Filed March 11, 1942 3 Sheets-Sheet 1Illlll Ill l lllllll v April 18, 1944.

w. H. ABBOTT STEAM HEATING BOILER CONTROL Filed March 11, 1942 3Sheets-Sheet 2 ML YTHOMA$ HQABBoi-T @MJFM Apnl 18, 1944- T. w. H. ABBOTTSTEAM HEATING BOILER CONTROL Filed March 1'1, 1942 5 Sheets-Sheet 3 TORADIATORS T9 (ATE-1'? on: BQILELR gwuc/vvtoz TH MAs W. H. Aseo r-Patented Apr. 18, 1944 UNITED STATES PATENT OFFICE 7 2,346,890 STEAMHEATING BOILER CONTROL Thomas w. H. Abbott, Baltimore, Md. ApplicationMarch ll, 1942, Serial No. 434,183

6 Claims.

The invention relates to a steam boiler control system principally foruse in the heating of apartments, industrial plants and the like, thoughit is also adapted to smaller installations, as in private residences.

The system as a whole, its various elements being interdependent butalso capable of separate use, comprises in connection with a steamboiler cf the type suggested or other suitable steam boilers with steamradiators, a float controlled condensate return valve, a floatcontrolled feed water valve, the floats for both valves being located inthe horizontal plane of the normal water level in the boiler, and a freeflowing air vent preferably of the balanced type, arranged to admit airto the boiler whenever the pressure drops below normal. This systembeing usually operated close to or preferably a little above atmosphericpressure. It is conceivable that for some purposes, the system may bearranged with suitable modification and equipment to operate at otherpressures, the purpose of the air valve being to cause the water levelat the location of the floats which control the condensate return valveand the feed valve to conform to the water level in the boiler,preventing over feeding due to vacuum in the boiler.

The purpose of the condensate return valve is to prevent backing up ofwater into the radiators and the return pipe and other pipes leading tothe radiators. It maybe employed without an automatic feed. The purposeof the feed water valve is to prevent overfeeding and, hence, filling ofthe steam space in the boiler and in the radiators with water and alsotoprevent feeding of water to the boiler through the automatic feed whenthe waterlevel has in someway become so low as to tend to causeoverheating, so that an influx of cold water would result in anexplosion.

The prior apparatus includes check valves intended to prevent backflowof the water toward the radiators and it also includes feedwater valveswhich are float controlled, but the check valves in the prior apparatushave not been elfective to prevent back flow of the water through thecondensate return pipe to the radiators, nor have the previous types offeedwater valves been effective to prevent over feeding of water to theboiler,

filling the steam space and tending to enter the radiators with harmfulresults, which are so well understood as not to require discussion.

The practical inoperativeness of the condensate return valves of theprior constructions is partly due to clogging of the seats with sedimentfrom the boiler and from other sources, and partly due to failure of thevalves to properly register with their seats, and failureof the valvesto seat quickly in response to the back flow of water from the boiler.Frequently the cause of the failure of the feedwater valves of the priorart has been the false water levels in the float chamber resulting fromthe creation of a vacuum in the boiler or sudden loss of pressure whichtends to prevent the water in the float chamber from seeking its gravitylevel, and hence, failure of the body of water in the float chamber tocorrespond as to the level of its surface, to the level of the water inthe boiler. This unsatisfactory operation is also due to failure of thevalves to seat because of unsatisfactory valve gear, and in someinstances to the location of the feed water valve float in the path ofthe returning condensate whereby'the position of the float was disturbedso that it failed to conform to the water level in the boiler.

All of these difficulties have been overcome in and by the apparatushereinafter described which has been found to operate perfectly forperiods of indefinite length, giving completely automatic regulation ofthe water level in the boiler, as well as complete absence of floodingof the boiler and radiators by overfeeding and complete absence ofbackflow through the condensate return pipe, the radiators beingpractically dry at all times. The boiler is also fully protected fromthe feeding of cold water when heating may have occurred due toreduction of the waterlevel.

In the accompanying drawings I have illustrated a boiler feed water andcondensate return control system embodying the features of my inventionin the preferred form in the drawings:

Figure l is a vertical section on the axis of the float casing orchamber containing the float which controls the feedwater valve and alsocontaining the float which supports the condensate return valve, and atthe topof this chamber is the condensate return valve chamber and valve,and the section also intersects the feed valve chamber and gearcasing'on a central vertical plane.

Figure 2 is a section through thefloat chamber looking downwardly fromline 22. in Figure 1, the scale being reduced Figure 3 is ahorizontallsection looking downwardly from the line 33'in Figure .1 andillustrating the feedwater valve gear.

Figure 4 is a horizontal section on the line 4-4 in Figure 1. I I

Figure 5 is an elevation partly insection show ing the air relief valvecasing and mechanism, the said view being broken away intermediately andincluding the connection to the boiler.

Figure 6 is a horizontal section on the line G-& in Figure lookingdownwardly from said line and showing the valve stem and balancingmechanism in top plan.

Figure 7 is a diagrammatic View of twin boilers to which the control isapplied showing the connections including the feedwater pipe and thecondensate return pipe and the casings of the various valves abovereferred to.

Figure 8 is a section corresponding to Figure 1, showing a form of thedevice in which the condensate return control valve chamber and floatchamber are separate from the .feed water control float.

Figure 9 is a section through the on the line 99, Figure 8.

Figure 10 is a diagrammatic view corresponding to Figure 7 showing theuse of the valve, Figure 8, independently of the feed.

Referring to the drawings by numerals, each of which is used to indicatethe same or similar parts in different figures; the construction showncomprises a pair of boilers I and 2, illustrated in connection with aninstallation to which the invention has been applied, the system beingof the gravity type, the pressure being normally about 2 lbs.above-atmosphere and dropping periodically to and slightly belowprevailing atmospheric pressure. The steam and condensate return pipesare indicated at 3 andA respectively, the radiators being above, andconnected in the usual manner to both pipes. This installation has beenreferred to as a dry system because of the absence of water from theradiators.

The system as illustrated also includes an automatic pressure control 5.connected to the steam chamber of the boiler by a pipe connection 6 andserving to open and close a damper or draft I in any suitable manner asby means of a flexible connection 8. This control serves to open thedamper and increase the fire when the pressure drops to or slightlybelow atmosphere. suitable equipment for adaptation of the system it maybe applied to systems operating at other pre The air or vacuum breakingvalve casing is indicated at 9.

The casing enclosing the condensate return valve and feed-water valvefloat is indicated at It! and the feedwatervalve casing also enclosingthe operating lever mechanism is shown at H, being connected directly tothe casing Hi. Pipe I! is a by-pass.

It may be noted that the condensate return pipe 4 extends downwardly oris looped downwardly at l2, extending below'the water level in theboiler and well down toward the bottom of the boiler and then extendsupwardly at M and vertically downwardly into the top of the chamber orcasing IS. The low point of the chamber or casing ill at I5, isconnected by a pipe IE to the boiler the pipe [6 being connecteddirectly'to the water space of boiler l The details are for illustrationonly, the system being capable of considerable variation. The boilersand 2 are connected below water level by pipe 11 and there is a feedconnection for special use as by means of a hose at H3.

Referring now to Figures 1,2 and 3, the condensate return valve and feedvalve float chamber is indicated by reference character 29 beingconnected at its lower end-to the pipe l6 which valve chamber.

W ith leads downwardly to the water space of the boilers and 2,preferably at a low point. The casing is connected above to the pipe 4which leads downwardly into the top of said casing H], particularly intoreturn valve chamber 21.

The condensate return valve 2| is shown as of the universal type havinga downwardly disposed seat 22 at the lower end of pipe 4, which ispreferably of the shape of a spherical section. The direction of theinflowing condensate return water tends to keep both the valve seat andthe valve surface free of sediment. The valve 2| is preferably openbelow and concave at 24 to assist in seating the valve in case of asudden influx of water from the boiler by way of pipe l6the primarypurpose of said condensate return valve being to prevent the backing upof water from --the boiler into the radiators, also to open freely topermit the return of condensed water to the boiler whenever theaccumulation of the condensate and the condition of the boiler pressurewill permit.

While many of the details are of importance, they are subject tovariation and rearrangement. The valve 2| is carried by a float 25which, as shown, is cylindrical and upright as to its axis, the floatbeing shown in depending relation to the valve and located in thevertical tube 26 which is open at both ends, The valve 2| is located ina funnel like chamber 21, to which the tube 261s secured at its upperend being shown as extending downwardly from the casing which is opendownwardly into the tube. The valve 2| is in its low or widest openposition supported by upright radial fins 28 which are located at thebottom of the chamber 21 being shown as extending horizontally inwardlyto the plane of the inner wall of tube 26. The condensate return valve,member 2|, as shown, as thus supported, is free to respond to the backflow and to conform to the seat 22 under any and all circumstances. Thefloat 25 which lifts the valve toward its seat when the water rises inthe tube 26 due to sudden increase of l pressure in the boiler isentirely free of the tube 26 which is much larger than the float 25, thetube 26 being of much greater diameter than the float 25.

The float chamber or casing 20 also contains an annular hollow float 29having a central opening, 30, which as shown contains or encloses thetube 25, being of considerably larger cross section than the tube 26,thus the float 29 is free to rise and fall without restraint from thissource,

In the normal position of the float, its central horizontal plane is atthe plane of the normal level in the boiler. This planemay be somewhatabove the section line 2-2 in Figure 1. In fact for the purposes of thisdescription, the position of the float valve 29 shown in Figure 1 may betreated as corresponding to. the normal water level in the boiler, thecentral horizontal plane of the float being at said water level.

The float 29 is providedwith a depending or downwardly extending stem oroperating rod 3|, the stem or rod 3| extends downwardly into thesub-chamber 32 of the float chamber 20, which sub-chamber is connectedat 33 to the feed water valve and gear casing I.

It may be noted at this point that the feed water pipe 34 preferablyleads in a downward direction into the casing H and that the seat 35 ofthe feed water valve 36 is downwardly disposed the feed water valve inturn indicated. at 31 being upwardly disposed and seating upward;

13'. The feed water valve 37 as shown has a downwardly spaced guide 38and a depending shank 39 extending through said guide. Said shank 39 isapertured horizontally at 40 to receive a normally horizontal valvelever 4| which in the form shown is pivoted at 42 at the right andextends horizontally to the left through the opening 40 which is shownas enlarged relatively to the cross section of the lever 4| and curvedas to its upper and lower walls, said walls being convex inwardly as at43.

-In the prepared form shown the pivot 42 is adjustably mounted on ascrew shank 44 which is threaded upwardly through the top wall or coverI l of easing I l and provided with an external engageable portion 45and packing nut 45'. The lever 4| rests at its outer end upon anactuating lever 41 which as shown is pivoted at '48 on an adjustablevertically slotted bracket 49, said pivot 48 being intermediate of thelength of the lever 4| and located between the shank 39 and the balllike head 50 at the outer or left hand end of valve lever 4|, remotefrom pivot or fulcrum 42.

The actuating lever 4'! extends to the left from its pivot 48 into thesubchamber 32 of valve cham ber 20, where it is provided with a fork 5!which straddles the lower end of the stem 3| between adjustable abutmentcollars 52 and 53 which engage the actuating lever 47, raising itsforked end 5| and lowering it or permitting it to descend as the float29 moves up and down with the change of level of the water in the floatchamber 20.

The actuating lever 41 is provided at the right in Figure 1, with arearwardl extending arm 54,

the direction of the first mentioned arm 55 to the left being treated asforward. The length of this rearwardly extending arm 54 which terminatesin a ball-like portion corresponds to th spacing of the ball 59 on thevalve lever 4| from said pivot 48 in a horizontal direction and to thespacing of shank or stem 39 from the pivot or fulcrum 42.

Float control feed valves of this and other types intended to permit orcontrol feeding of Water to a boiler whenever the water level dropsbelow its predetermined normal, previously known have provedunsatisfactory because of the tendency to overfeed and fill the steamspace in the boiler and part or all of the steam space in th radiatorsand steam pipes with water. the creation of a vacuum or to reduction ofpressure in the steam space and in the radiators which is generally dueto condensation in the radiators when the fuel gets low or to a more orless sudden reduction of the boiler temperature as in the feeding ofcoal to an overfed furnace. Such reduction of temperature causes quickcondensation with a correspondingly quick reduction of pressure to orbelow atmospheric pressure, the pressure in the boiler being thusreduced below that in the float chamber where air is at atmosphericpressure or at slightly higher pressure, pocketed, or a column ofcondensate has accumulated in the return pipe 4. This difference inpressure between the boiler and the float chamber causes a lower waterlevel in the float chamber or casing 20 than that existing inthe-boiler. This may be referred to as a "false water level" in thefloat chamber. This false water level being but slightly below normalprevents the feed water valve from rising to the level of the water inthe boiler and thus causes feeding of water to the boiler Without regardto the existing water level therein so that with anextended period ofvacuum in the boiler the steam space may be almost com- This is mainlydu to r pletely filled, frequently backing the water up into theradiators, a condition which is known to have objectionable results.

In the present system this difiiculty has been overcome by the provisionof a free flowing air valve, preferably the balanced type so that it maybe adjusted to admit air freely to the boiler when the pressure goesbelow atmospheric or otherwise below normal. While this valve isintended to be used to admit air at atmospheric pressure, it isconceivable that it might be used with boilers working at higherpressures by connection of the valve to a supply of air or other gasunder suitable pressure. This valve is preferably mounted directly on orconnected directly to the boiler to provide a free flow of air and thusto accomplish practically instantaneous filling of any vacuum which mayoccur in the boiler, hence equalizing or substantially equalizing thewater level in the float chamber with that in th boiler. While the valveas shown is mounted directly on the boiler, and it is believed to bebest located in that way, it may be connected by a pipe which is to thebest advantage so arranged as to g ve the inimum of friction incident tothe flow of air and hence to give quick equalization of the pressures. Aform of air valve suitable to the system is illustrated in Figures 5, 6and '7.

The air valve assembly -60 comprises a casing 9. This casing contains adownwardly disposed spherical seat Bl, formed on a valve seat insert 62,threaded into an upwardly disposed opening in said casing, indicated at63. This opening is'provided with a perforated upright turret 64, whichsurrounds the opening and extends upwardly therefrom, the perforations65 being near the top, and protected by a cap or mufiler 66, of largerdiameter than the turret '64, and having a depending skirt 6'!surrounding the turret 64.

The casing 60 also encloses a valve member 68 cooperating with seat 6|.This valve as shown has its seating surface in the form of a sphericalsection and provided with a depending stem 69 which as shown iscontrolled by guides 10 and Hi. The valve stem 69 is shown as providedwith upper and lower opposite rounded abutments II. The valve or valvemember 68, with its stem 69, is carried by a balance lever 12, pivotednear its center, as on horizontal transversely extending knife edges 13,which engage knife edge seats 14 removably mounted in the casing 60 ason screw carriers 14' as .best shown in Figure 6. The lever 72 is forkedat one end at 15 to straddle the stem 69 between the abutments II andarranged to engage the upper and lower abutments alternatively.

The lever 12 and valve member 68 are shown as balanced by a weight 16adjustably mounted on the end of the lever which is opposite to the fork15. As shown the weight 16 is threaded on the end of the lever arm, andheld in position by a lock nut ll-the details being subject to variationwithout departure from the principles of the invention. 7

It should be noted that the air valv casing 69 is connected to the steamspace of the boiler by a pipe 79 of sufficient cross section to providea free flow of air to the boiler in response to each drop of pressure.The valve member '68 is preferably open and hollow or concave beneath at62' to provide for pocketing the back flow to give quick closing toprevent escape of steam. The operation of the control will be more fullydiscussed in connection with the complete disclosure.

Figures 8, 9 and 10 relate to a system in which the condensate returnvalve is separate from the feed water control in which the feed of waterto the boiler is controlled by hand or by some other means not directlycombined with the return of the condensate to the boiler.

Figure shows diagrammatically a steam heating system having a boiler,99. This boiler is connected by one or more steam pipes 8i to the steamradiators in the building not shown. The illustration also includes apressure controlled regulator 82, connected to the steam space of theboiler by a pipe 83 to receive pressure therefrom and to the draft ordamper 84 by a flexible member 85, any control being usable for thispurpose. Illustration Figure '7 is for example only.

The system also includes condensate return pipe 89, leading downwardlyto a low point 81, which is preferably near the bottom level of thewater in the boiler as shown at 88, and upwardly to a high point 89above the water level in the boiler, and then downwardly entering thetop of the condensate return valve casing 99. From the bottom of thecasing 90, a pipe 9! leads downwardly entering the water space of theboiler at a low point as indicated in 92, which is near the bottom ofthe boiler. There is also a by-pass connected around the casing 99, asindicated at 93. The various connections in the diagram and in thediagram Figure 7 are supplied with suitable shut-off valves as in othersystems of this general type. Figures 8 and. 9 show the condensatereturn valve assembly 99. The valve member 99 is mounted in the chamberor casing 99, and connected to the radiators by the condensate returnpipe 89, leading downwardly to the top of the casing 94, and by a returnpipe 9|, leading to the water space of the boiler at a low point 92.

The pipe 86 leads downwardly from high point 89 to and through a valveseat which may be formed on the valve seat ring 95. On the lower face ofthis is formed a downwardly disposed valve seat 99. This seat as shown,is a spherical section or zone and cooperating with this seat is apoppet valve 99, having an upwardly disposed valve seating surface 91,shown as in the form of a spherical section. This valve 99 is preferablyconcave beneath as at 98 and open to assist in immediate closing bylifting the valve toward the seat in case of a sudden tendency to backflow on account of increased pressure in the boiler or an influx of feedwater. The valve member 99 is provided witha depending valve supportingfioat 199, shown as of cylindrical form and extending downwardly withina tubular portion Ifil of said casing 99, to the bottom of which returnpipe 9I is connected.

In the form shown the portion of the casing 90 beneath and surroundingthe seat 99 and valve member 99, is in the form of a frusto-conicalfunnel member I92, this arrangement and other details are subject tovariation, the purpose being to provide an easy down flow of the waterfrom pipe 89 through the seat 96 to and around the valve, and beneaththe'same to the tubular portion WI and downwardly to casing 99 andthrough same to the boiler.

The valve member 99 is shown as supported in open position by means ofradial fins I93, which are spaced about the chamber I92 at the bottomthereof and extend upwardly to a sufiicient degree to provide a freeflow of water past the valve in its lower and most widely open position.

A feed water inlet to the boiler is shown at the left in Figure 10 atI94. This may be hand controlled or any suitable automatic feed may beemployed. In the various forms of the invention, there may be a draincock I05, in the condensate return pipe at the bottom of the loop. Themain purpose of this is to provide for the release of sediment from theradiators and boiler which in existing systems tends to accumuate on theseats and valves and prevent satisfactory closing.

In the operation of the system, reference being had first to Figures 1to '7, the condensate from the radiators, the pipe 4 being connected toa low point of each radiator in the system, flows downwardly through thevalve seat 22 which may be formed on the insert 23. From seat 22 itflows to and through the chamber 21, the valve 2| being open anddownwardly through the tubular fixture 26 into the chamber 20. Assumingthat the pressure in the boiler is low at this time the condensate tendsto flow through the pipe I6, to the water space of the boiler. From timeto time a column of water may accumulate in the pipe 4, and when thepressure in the boiler drops to or below atmosphere or below normalboiler pressure due to consumption of the fuel supply in the furnace orto feeding of coal to the top of the fire, there may be a rush of waterdownwardly through the seat 22, which, if it were permitted to contactthe feed water control float 29, would change its position so that itwould not correspond to the water level in the boiler and hence wouldinterfere with the regulation and control. of the feeding of water tothe boiler at water level below normal,

The installation as shown in Fig. 1 has the advantages of a single floatvalve chamber for the feed water return valve, and the feed watercontrol valve, and it is important that the condensate in returningthrough the combined float chamber passes through tube 26 in the opening39 in float 29 and does not interfere with the conformation of the feedwater control float to and with the level of the water in the boiler astransmitted to the float chamber, and hence does not interfere withregulation of the feed.

It is also to be noted that the condensate return valve has its seatdownwardly disposed with the water flowing downwardly therethrough sothat the sediment which accumulates to a considerable degree in theradiators, tending to return with the condensate, does not accumulate onthe seat and further the downward flow of the water over the valveseating surface at 2| tends to clear the valve surface of sediment. Itis also of interest that the valve and the seat 22 are preferably of theuniversal type so that the cocking due to side pressure on the valve orany slight disalignment does not prevent it from engaging the seat andforming an effective closure. Further, the valve is free to movevertically to and from its seat in opening and closing the float 25being considerably smaller than the tube 26 which serves a guidingfunction to a sufficient degree to keep the valve 2| in approximate algnment with th at and hence in seating position.

It is also notable that the valve 2I supported by the float 25 movesupwardly toward its seat whenever the water in the tube 26 rises to theproper point or there is a tendency to back flow of Water into theradiators, and this valve is caused to contact its seat due todifference of pressure, i. e. vacuum in the radiators, as well asbuoyancy so that there is no possibility of back flow of water to theradiators and the water is discharged from the radiators into the boilerWhenever it accumulates, even" small quantities, provided there is adrop in" pressure in the boiler which permits opening of the valve 2|.Such reduction of pressure is bound to occur at comparatively frequentintervals due to variation of the fire or feeding of coal to the top ofthe fire, the overfeed type of furnace being generally used, and evenwith other types of furnace, there is sufficient variation to permit thecondensed water to return to the boiler with sufficient frequency tokeep the radiators free of Water, The down flow through the downwardlydisposed seat is effective in clearing the seat and valve of scale andsediment from the boiler and radiators and the spherical contours of theseat and the seating surface of the valve contribute to theeffectiveness of the closure.

The condensate return valve is in many ways independent of the controlof the feed water and for this reason it is shown separately in Figure 8in connection with a boiler, which may have the water fed to it by anymethod, either hand controlled or controlled by any device separate fromthe condensate return control valve.

The illustration, Figure 1, includes, as already pointed out, thecombined float chamber 20, and feed water valve casing H, the floatchamber contains float 25 which supports the condensate return valve 2|,and also contains the float 29 which controls the operation of the feedwater valve 3'! through and by way of the feed water valve operatingassembly 33 in the chamber II.

The feed Water valve seat 35 is preferably downwardly disposed, beingfed from a water pressure supply pipe 34, and the valve 31 closesupwardly into contact with said seat. The feed water control valve float29 in the form shown has a depending stem 3| secured to and extendingdown from a spider 23 which is secured-to the bottom of float 29,spanning the opening therein, the float being for the purposes stated,preferably an annular float permits the condensate return to passtherethrough. The condensate return valve float may, however, be placedin a separate chamber, the construction shown having the importantadvantage of simplicity of installation and compactness.

The depending stem or rod 3| of float 29, in the form shown engages thecontrol lever 55 by way of upper and lower abutments 52 and 53, whichare spaced apart whereby the motions of the float are communicated inmodified form through the lever 55.

In accordance with the preferred operation, the feed water valve 31 isclosed when the float 29 moves above its mid-position in correspondenceto the normal water level in the boiler thus preventing overfeeding andit is also closed when the float sinks below the normal water level inthe boiler as communicated to float chamber 20, thus preventing feedingof water to the boiler when the recession of the water to a dangerouslow point may have caused overheating of exposed parts of the boiler asthe crown sheet;

Such feeding of water to the boiler when thus overheated is probably thecommonest cause of boiler explosion, or at least it is a fruitful causeof such explosions.

There may be a degree of lost motion between the abutments 52 and 53 andin the forked end of the lever 41 which may permit slight variations ofposition of the float without change of the position of the valve or ofthe lever 41.- Mainly it provides freedom of the feed valve operatingmechanism. The valve operating leverdl being pivoted at one end andconnected intermediately of its length to the lever 31 as by oppositeabutments 43 and resting at its extreme outer end at 50 on th lever 41,between its pivot 48 and the fork 5|, i raised closing the valve 31 whenthe float 29 rises above the position corresponding to normal waterlevel in the boiler when the water level drops slightly below normallever 41 is lowered, lowering the end 58 of valve lever 4| causing'thevalve to be opened to admit Water to the boiler from the feed pipe 34,and in the extreme low position of the float 29, the arm 55 of operatinglever 47 moves downwardly raising the rear ball like end 54 of lever llon the opposite side of pivot 48 from the fork end 5!, to contact thevalve lever M from beneath, raising the same and closing the valve 3'5.This only occurs when the water level has dropped to a danger pointwhere overheating with danger of explosion due to introduction of coldwater would result. This condition is of most infrequent occurrence, thesystem being capable of completely automatic operation for periods of amonth and longer.

When this position of the parts has been reached and the valve 31 hasbeen closed, no water can be fed to the boiler unless it be with thefull knowledgeand intent of the operator using a hose or other specialequipment provided for this purpose as suggested at H3. Thus theattention of operator is calledto the condition of the boiler causinghim to take the necessary precautions. It is to be noted'in thisconnection that when the water reaches such low levels the condensatewill have been pre-' viously drained from the radiators and there islittle water to be returned to'the boiler at this time from thecondensate returnline. In fact, the heating system to which the controlhas been applied in the disclosure, is known as a dry open system inthat the radiators and steam pipes are practically dry at all times andfree of condensed water as well as back flow, the condensed water beingpromptly returned almost as soon as it accumulates. On the other handany tendency to back flow forcin water upwardly through the tube 26operates both by impact and buoyance of float 25 to close the valve 2!instantaneously and as soon as thepressure in the boiler drops, thevalve opens and releases the condensate, returning it to the boiler. Theconcave underside of the valve at 24 has an important function inassisting in the closing of the valve due to impact of water as byhuddling.

Fluctuations of radiator and boiler temperatures producing periodicrecession of boiler temperature cause corresponding recessions ofpressure with sub-atmospheric or equivalent low pressures in the boilerotherwise referred to as vacua, which by reducing the pressure in thepipe I5 tends to lower'the level of the water innthe chamber 20, whereair is frequently trapped to levels below that existing at the time inthe boiler such subwater levels in the float chamber may be referred toas false water levels in the float chamber. These levels are slightlybelow the existing water level in the boiler and tend to slightly lowerthe feed valve control float 29 holding the valve 3? in open positionand causing floodingof the boiler and filling of the steam space withwater which also enters the radiators. This is the most frequent causeof ineffectiveness or inop-.

erativeness of the apparatus as previously applied to feed watercontroLsuch systems having been on the market with some variations for aconsiderable period.

In the present control this difficulty has been completely overcome bythe use of a balanced or equivalent type air valve which opens freely toadmit air to the boiler in response to subatmospheric pressures in theboiler or equivalent pressures if pressures of steam and air areemployed which are more widely different from existing atmosphericpressures than those discussed.

This air release valve or vacuum breaking valve in the form ofsystemwhich has been tested and disclosed herein as an embodiment of thepresent invention, is directly connected to the steam space of theboiler by means of a pipe 19, being located in a chamber 60 in casing 9,and suitably balanced to open and admit air freely to the steam spacewhenever the pressure in the boiler recedes to the predetermined degreebelow normal, in this instance below atmosphere. To this end the weight16 which is used to balance the valve and normally to hold it in closingrelation to the seat, may be adjustable along lever arm 12 to give thedesired spread, usually very slight between atmospheric pressure and thepressure at Which the valve opens. This determines the degree of vacuumwhich may exist in the boiler. Whenever the boiler pressure recedesbelow atmospheric pressure or other air pressures employed the valvebeing open beneath at 88 and concave to receive and impound steam aportion of the steam which tends to escape closes instantaneously due toimpact and steam pressure and thus retains the full boiler pressure.However, whenever there is a vacuum or a drop below normal pressure inthe boiler, the valve opens instantaneously till stopped by guides 79',providing a free flow of air into the boiler and thus equalizing thepressure in the boiler with that inthe chamber 20 and preventing falselevels of the water in the float chamber, i. e., causing the float 29 toconform to the water level in the boiler and thus giving accurateregulation to the feed at all times and particularly preventing floodingof the boiler and the radiators.

The successful automatic control of the boiler feed in this type ofsystem is regarded to an important accomplishment various apparatus forthis purpose having been on the market but having proven almost whollyineffective to accomplish continuously automatic control.

In the more limited view of the invention, the arrangement as well asthe various valve assemblies and the combination of the same with asteam boiler system are regarded as new and constituting importantcontributions to the results obtained.

The apparatus, Figures 8 to 10, has the condensate return valve operatedindependently of the automatic control of this feeding of water to theboiler. Its construction and operation are believed to be clear from thedescription of these figures taken with the preamble to thespecification and the description of the operation of the first form ofthe invention,

I have thus described a steam heating system and a feed water andcondensate return control for the same, the system and control asdescribed embodying features of the invention in what is now regarded asthe preferredform, the description being specific and in detail in orderthat the manner of constructing, applying, operating and using theinvention may be fully understood; however, the specific terms hereinare used descriptively rather than in a limiting sense, the scope of theinvention being defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination in a heating system having a steam boiler and steamradiators above the boiler, of a float controlled feed water valve, afeed water pipe leading from a source of supply to the boiler andcontrolled by said valve, a float chamber at the normal surface level ofthe water in the boiler, a float in said chamber controlling said valvewhich is connected to said float, a condensate return leading to saidchamber which is connected to the water space of the boiler and acondensate return control valve in said return and a float operativelyconnected to said latter valve and also located in'said chamber, therising of the Water level in said chamber, abovev normal serving toclose both said valves and the falling of the water level below normalserving to open said valves.

2. The combination in a heating system having a steam boiler and steamradiators above the boiler of a float controlled feed water valve havinga float chamber at the normal water level of the water in the boiler, afloat in said chamber controlling said valve a condensate return leadingto said chamber which is connected to the water space of the boiler anda condensate return control valve in said return and a float operativelyconnected to said latter valve and also located in said chamber, thefeed water valve float being of annular shape with a central verticalopening and the condensate return control valve float being located insaid opening and spaced inwardly from the wall of said opening toprovide for the passage of the returning condensate through to saidopening.

3. The combination in a heating system having a steam boiler and steamradiators above the boiler of a float controlled feed water valve havinga float chamber at the normal level of the water in the boiler, a floatin said chamber controlling said valve, a condensate return leading tosaid chamber which is connected to the water space of the boiler and acondensate return control valve in said return and a float operativelyconnected to sai l latter valve and also located in said chamber, thefeed water valve float being of annular shape with a central verticalopening and the condensate return control valve float being located insaid opening and spaced inwardly from the wall of said opening toprovide for the passage of the returning condensate through to saidopening, and means for diverting the condensate return directing it intosaid opening and preventing it from contacting the top surface of thefeed water valve float.

4. A condensate return valve assembly for a steam heating system havinga boiler means for maintaining said boiler pressure near that of theatmosphere, said system having radiators above the boiler and acondensate return pipe leading downwardly from the radiators, saidassembly comprising a valve chamber having a downwardly disposed seatand a valve member having an upwardly disposed seating surface, a floatcham' ber connected to said valve chamber, said valve chamber and saidfloat chamber being adapted to be located in said return pipe whichconnects the float chamber to the boiler at a point beneath the waterlevel, a float in said chamber connected to said valve to raise it intoclosed relation to the seat when the water level rises above normal anda vacuum breaking valve connected to the steam space of said boiler, andopening inwardly to introduce air into said boiler and into said systemwhen the water pressure drops below normal.

5. A condensate return valve and feed water control assembly for a steamheating system comprising a float chamber, a feed water valve chamberand a cooperating valve and seat there? in, a feed water pipe leading tosaid seat, a feed water valve float of annular shape having a centralopening means connecting the feed valve float to the feed valve to closethe lattei'ift when the water level rises above normal and to; belownormal,

open it when the water level drops I said float chamber being adapted tobe connected member having an upwardly disposed seating surface thevalve chamber surrounding said con,-

densate return valve member and seat, said chamber having a downwardlydisposed tube ex: tending into the opening in said annular float andsaid condensate return valve having a float extending downwardly intosaid tube, said tube serving as a guide for said valve by contact ofsaid float therewith, and passage means connecting said chamber to theboiler below the water level therein.

6. The combination with a steam boiler and radiators of a float operatedfeed-water valve, a pipe leading from a source of water supply to thewater space of said boiler, a float chamber connected to said waterspace and located at the Water level, a float therein, said valvecontrolling the passage of water through said pipe, and means connectingsaid float to said valve to close the same when the water level goesabove normal and also when the water level recedes to a pie-determinedlevel below said normal, the valve being open at intermediate levelsbetween said upper and lower level, means for controlling the pressurein the boiler to remain in the vicinity of atmospheric pressure and avacuum breaking valve connected to the steam space of said boiler toprevent the establishment of a vacuum in said boiler, and hence tocontrol the water level in the chamber to correspond to the water levelin the boiler.

THOMAS W. H. ABBOTT.

